Plasterer&#39;s finishing tool



July 2, 1963 P. B. DORNBOS 3,095,594

PLASTERER'S FINISHING TOOL Filed April 29, 1960 INVENTOR PETER 5. DORA/B05 F65 QM W ATTORNEYS United States Patent 3,095,594 PLASTERERS FINISHING TOOL Peter B. Dornbos, 1929 Mclllwraith St., Muskegon, Mich. Filed Apr. 29, 1960, Ser. No. 25,574 3 Claims. (Cl. 15235.4)

This invention relates to a plasterers finishing tool. More particularly, this invention relates to an improved plaster trowel, angle plow, angle float, etc. used for finishing the surface of a plastered wall.

Finishing tools presently in existence for densifying and smoothing a finishing coat of plaster utilize a handle rigidly secured to a member having a flat working surface. The member including the flat Working surface is relatively thin in order to keep the tool light in weight and reduce its cost. This surface is stroked back and forth over the wall, pressure being applied as the member ismo'ved. This movement of the tool under pressure across the surface of the wall smooths the plaster which has been applied thereto and densifies it, securing it on the wall. Since great pressure must be applied to the tool in order to properly smooth the plaster, and since the member including the flat working surface is relatively thin, the tool tends to bend and flex. This flexing gives rise to two disadvantages. First of all, the flat working surface of the tool tends to bend transversely to the direction of movement thereof. Thisresults in a wavy finished coat of plaster because the tool tends to shape itself to the configuration of, wells or rises which might have been created when the base coat was applied to the wall. Secondly, the tool tends to bend or flex with the direction of movement thereof. This means that even though the operator attempts toapply only an edge of the tool to the wall as he moves it, actually the entire area along the trailing edge of the working surface Will engage the wall. Thus, the amount of pressure actually applied to the wall is greatly decreased since the pressure is distributed over a much greater area than intended. This flexing and bending of the tool often results in a finished surface of poor quality, in a surface which is not smooth, even though the operator is fatigued from applying maximum pressure to the tool. It is an object of the present invention to provide an improved plasterers finishing tool which overcomes these difiiculties.

Another object of this invention is to provide a plasterers finishing tool of a structure such that reduced presure is required to Work the tool over the wall, thus reducing the fatigue on the operator.

Another object of this invention is to provide such a tool which reduces flexing under pressure, thus eliminating a wavy, finished surface by filling voids and leveling raised portions in the base coat of plaster.

Another object of this invention is to provide such a tool enabling the operator to apply increased pressure to the wall through less effort, the increased pressure densifying the surface of the finished wall giving a finer quality to the work.

Another object of this invention is to provide such a tool which may utilize a less expensive grade of steel due to its particular construction.

A still further object of this invention is to provide such a tool which achieves all of these objects, yet is simple in construction and inexpensive to fabricate.

These and other objects of this invention will become obvious to those skilled in the art of plastering tools upon reading the following specification in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side, elevational view of a plaster trowel utilizing this invention;

FIG. 2 is a cross sectional view taken along the plane II--lI of FIG. 1;

3,095,594 Patented July 2, 1963 FIG. 3 is an enlarged view of the encircled portion of FIG. 2;

FIG. 4 is a bottom view of the trowel shown in FIG. 1; and

FIG. 5 shows the tool comprising this invention during its operation.

Briefly, this invention relates to a plastering finishing tool for densifying and smoothing the surface of a wall during the plastering thereof, including a member having at least one flat working surface for engaging the wall and an elongated, rigid strip of very small cross section secured along at least one edge of this member, the strip extending from the flat working surface.

Referring more specifically to the drawings, reference numeral 1 designates a plastering trowel used for smoothing the surface of a wall during the plastering thereof (FIG. 1). The trowel 1 includes a handle 2 and a 'member 3 having a flat working surface 4 (FIG. 2).

Up to this time, it has been necessary that the member 3 be comprised of an expensive, high grade steel because of the pressures to which it is subdued when moving it along a wall. It will become apparent that this is no longer necessary from the following description of the novel structure comprising this invention.

Secured to the member 3, along the opposed edges of the working surface 4 thereof, are elongated, rigid strips 10. These strips are of a very small cross section. In practice, it has been found that a strip 10 having a cross section of approximately one-sixteenth inch by onesixteenth inch achieves the results of this invention. It has also been found that these strips may be suitably bonded to the working surface 4 of member 3 by means of a high strength bonding glue. A similar elongated strip 11 is also secured to one of the edges connecting the strips 10 (FIG. 4), the purpose of which will be explained hereinafter.

This new and improved plaster trowel operates as follows. The trowel is moved from left to right as shown in FIG. 2, being positioned however at an angle with respect to the wall. This is clearly shown in FIG. 5, the finished coat of plaster being designated by the reference numeral 20 and plaster being densified on the wall designated by the reference numeral 21. Without the addition of the elongated strips 10, movement of the member 3 along the wall would cause the tool to flex both with the direction of movement of the trowel and transversely to its direction of movement, thereby creating the disadvantages noted hereinbefore. However, the strip 10 acts as a strengthening member and restricts buckling or flexing of the working surface transversely to the direction of movement of the tool. The strip 10 functions as a strengthening beam to prevent such flexing. Therefore, the trailing edge of the tool cannot conform to Wells or rises in the first plaster coat, rather, the edge is rigidly retained to a straight line and all wells are filled in and rises are cut off. This assures a smooth finish coat.

Secondly, and more important, is the fact that the strips 10 positively assure that only a very, very small area of the plaster trowel engages the wall while the trowel is moved therealong. Without the strips 10, the working surface 4 would flex slightly with the direction of movement and thereby allow an area of the working surface along the trailing edge to engage the wall. It is well known that great pressure is needed to density the finishing coat in order to give it a high quality. Also, the operator of the tool naturally must supply a great deal more pressure if a greater area of the trowel engages the wall. With the strip 10 extending from the working surface 4, the operator is assured that only an extremely small trailing edge of the trowel will engage the wall as shown in FIG. 5 because even if the trowel flexes with the direction of movement, only the strip engages the wall. With this simplified addition to an ordinary plastering trowel, a tool is provided whereby the operator can actually perform a better job with less effort. This is because of the small area of the trowel which engages the wall, requiring much less pressure on the part of the operator. However, since the strip 10 assures that only a minute area of the trailing edge will engage the wall, a lessening of pressure on the part of the operator will still result in greater pressures being applied through the area which actually does engage the wall.

It is to be specifically understood that this invention is not limited to trowels. This invention may be used in any plasterers finishing tool having more than one fiat surface, such as an angle plow or an angle float. Further, this invention is not limited to hand tools since the strips 10 may be applied to the flat working surface of a powered plastering tool.

The addition of strip 11 to the surface 4 achieves the results described hereinbefore in the event the operator uses the narrow end of the tool.

It will now be seen that this invention has provided a plasterers finishing tool having a reinforced edge which tends to hold the trailing edge of the working surface in a straight line, giving the wall a smoother appearance by filling in voids and leveling raised areas. Reduced pressure is needed to work the trowel because only the elongated strip engages the wall and therefore the operator does not become fatigued as easily. However, even though less pressure is applied by the operator, the actual pressure applied to the wall is increased because of the small surface area of the trowel actually engaging the wall. A superior quality of work can be given because this greater pressure densifies the surface of the wall, Even though achieving these results, this plastering tool may be cheaply manufactured because the working surface of the trowel does not engage the wall as do trowels presently in existence. In short, this tools design assures a more even, smoother application of the finished coat of plaster through less effort on the part of the operator.

While only one embodiment of this invention has been shown and described, it may be possible to practice this invention through the utilization of certain other embodiments. These other embodiments are included Within the spirit and scope of this invention as defined in the following claims.

I claim:

1. A plastering finishing tool for densifying and smoothing the surface of a wall during the plastering thereof including a member having at least one flexible, thin, flat working surface for movement along the wall, an elongated flat rigid strip of small cross section secured along the edge of said surface used for applying pressure to the wall, said strip extending from said working surface a uniform distance.

2. A plastering finishing tool as defined in claim 1, said surface having a plurality of edges for applying pressure to a wall, and one of said strips secured to each of said plurality of edges.

3. A plastering finishing tool as defined in claim 1, said strip bonded to said surface.

References Cited in the file of this patent UNITED STATES PATENTS 397,129 Hill Feb. 5, 1889 425,110 Smith Apr. 8, 1890 745,126 Warson Nov. 24, 1903 1,321,532 Mann Nov. 11, 1919 1,763,066 Rooney June 10, 1930 2,275,713 Ahlborg Mar. 10, 1942 

1. A PLASTERING FINISHING TOOL FOR DENSIFYING AND SMOOTHING THE SURFACE OF A WALL DURING THE PLASTERING THEREOF INCLUDING A MEMBER HAVING AT LEAST ONE FLEXIBLE, THIN, FLAT WORKING SURFACE FOR MOVEMENT ALONG THE WALL, AN ELONGATED FLAT RIGID STRIP OF SMALL CROSS SECTION SECURED ALONG THE EDGE OF SAID SURFACE USED FOR APPLYING PRESSURE TO THE WALL, SAID STRIP EXTENDING FROM SAID WORKING SURFACE A UNIFORM DISTANCE. 